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    <title>cepstrum</title>
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    <center>Scilab Function</center>
    <div align="right">Last update : April 1993</div>
    <p>
      <b>cepstrum</b> -  cepstrum calculation</p>
    <h3>
      <font color="blue">Calling Sequence</font>
    </h3>
    <dl>
      <dd>
        <tt>fresp = cepstrum(w,mag)  </tt>
      </dd>
    </dl>
    <h3>
      <font color="blue">Parameters</font>
    </h3>
    <ul>
      <li>
        <tt>
          <b>w</b>
        </tt>: positive real vector of frequencies (rad/sec)</li>
      <li>
        <tt>
          <b>mag</b>
        </tt>: real vector of magnitudes (same size as <tt>
          <b>w</b>
        </tt>)</li>
      <li>
        <tt>
          <b>fresp</b>
        </tt>: complex vector</li>
    </ul>
    <h3>
      <font color="blue">Description</font>
    </h3>
    <p>
      <tt>
        <b>fresp = cepstrum(w,mag)</b>
      </tt> returns a frequency response <tt>
        <b>fresp(i)</b>
      </tt>
    whose magnitude at frequency <tt>
        <b>w(i)</b>
      </tt> equals <tt>
        <b>mag(i)</b>
      </tt>  and such
    that the phase of <tt>
        <b>freq</b>
      </tt> corresponds to a stable and minimum phase
    system. <tt>
        <b>w</b>
      </tt> needs not to be sorted, but  minimal entry should not be
    close to zero and all the entries of <tt>
        <b>w</b>
      </tt> should be different.</p>
    <h3>
      <font color="blue">Examples</font>
    </h3>
    <pre>

w=0.1:0.1:5;mag=1+abs(sin(w));
fresp=cepstrum(w,mag);
plot2d([w',w'],[mag(:),abs(fresp)])
 
  </pre>
    <h3>
      <font color="blue">See Also</font>
    </h3>
    <p>
      <a href="frfit.htm">
        <tt>
          <b>frfit</b>
        </tt>
      </a>,&nbsp;&nbsp;</p>
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